In a bowl, stir together water, ketchup, soy sauce, cornstarch, honey, crushed red pepper, and ground ginger. Set aside.
Heat oil in a large skillet over medium-high heat. Stir in green onions and garlic; cook 30 seconds. Stir in shrimp, and toss to coat with oil. Stir in sauce. Cook and stir until sauce is bubbly and thickened.